Being able to easily alert emergency responders in case of an automobile accident is highly desirable. Mobile application service providers (such as OnStar®) address this need for their subscribers by offering an emergency call button located within reach of the driver of an automobile. Upon pressing the emergency call button an emergency telephone call is placed from a cellular telephone which is embedded in the vehicle through a wireless telecommunication network and a public switched telephone network to a service center operated by the mobile application service provider. An emergency call to the service provider may also be initiated automatically, e.g. upon airbag deployment.
In case of an incoming emergency call the mobile application service center silently obtains vehicle position information, e.g. information from a GPS receiver that is also embedded in the vehicle. The mobile application service center as part of an emergency assistance service informs public safety authorities of the emergency and conveys the vehicle's position. The emergency assistance service is typically available only to those who register (for a fee) with the mobile application service provider. Registration with the mobile application service providers includes an underlying registration with the wireless telecommunication network. Several elements of one such system are described in U.S. Pat. No. 6,812,832 (Lobaza), which is hereby incorporated by reference.
The embedded cellular telephone may also be used to place hands free telephone calls. Dialing the embedded cellular telephone may utilize a speech recognition engine that is capable of recognizing spoken telephone numbers or voice tags associated with telephone numbers. To facilitate dialing the embedded cellular telephone may also be connected to an external keypad, e.g. a telephone-style keypad located in the vehicle's dashboard or a virtual keypad displayed on a touch screen display. The external keypad may communicate with the embedded cellular telephone by sending a telephone dial command message through the vehicle communication network. The embedded cellular telephone is accordingly configured to receive telephone dial command messages on the vehicle communication network and establish a telephone call to the requested telephone number.
US law obligates commercial mobile radio service providers to transmit all wireless 911 emergency calls without respect to their call validation process to a Public Safety Answering Point (PSAP), or, where no Public Safety Answering Point has been designated, to a designated statewide default answering point or appropriate local emergency authority. The law extends to voice capable cellular telephones embedded in vehicles. An embedded cellular telephone can hence be used in an emergency to directly alert public safety authorities by dialing 911 regardless of registration status with the mobile application service provider or the underlying wireless telecommunication network. However, the user interface provided to dial 911 is inferior to single button activation and may e.g. require use of the voice recognition interface. Changes in an operator's voice during an emergency frequently cause the voice recognition engine to fail detecting a spoken “dial 9-1-1” command and thereby preclude the operator from receiving the help he is seeking.
What is therefore needed is a method for combining the benefits of legally mandated free wireless 911 access to a Public Safety Answering Point with the advantageous single button user interface for placing emergency calls to a mobile application service center.